Thermal-shutdown protection may facilitate preventing damage in semiconductor devices e.g. in the junction region due to prolonged operation at high temperatures. For instance, reliable and continuous operation of integrated circuits may be facilitated by junction temperatures in a chip not exceeding values of e.g. 150° C.
Thermal-shutdown sensors may be integrated in a semiconductor device with the capability of sensing chip temperature and automatically produce power shut-off, e.g. until chip temperature returns to a level considered to be safe.
In certain devices including sensitive circuits (e.g. microcontrollers or logical circuits that control circuits in a chip such as driver, core, oscillator or memory circuits and the like) thermal-shutdown may occur and interrupt operation before e.g. a core is in a position to detect an event leading to high temperature dissipation. Also, the sensitive circuit may be undesirably exposed to high temperatures.
In certain applications, a circuit, such as a CPU, may be housed in a separate package, so that thermal dissipation is unlikely to affect processor performance. However, an e.g. embedded CPU may be shut-off (and possibly damaged) as a result of high power dissipation from other (e.g. internal) outputs. Device logic may be corrupted, with a control circuit such as a microcontroller prevented from achieving a safe condition as a consequence of being “off”.
U.S. patent publication 2015/0208557 A1 discloses a method for independent shut-off of a subset of power stages. Such an arrangement includes thermal sensors associated to functional “clusters”, with the capability of avoiding a complete shut-off of the device by keeping active (only) those functions which are not affected by a thermal event.
While providing a satisfactory degree of operation, it is felt that such an arrangement may be further improved e.g. by avoiding that an embedded CPU may be undesirably damaged as a result of a temperature increase caused by high power dissipation by other junctions (e.g. device outputs) in the same chip.